This patch changes chasquid-util's subcommands and parameters to
(hopefully) make them more user friendly and intuitive by default.
The changes include defaulting the configuration to /etc/chasquid, and
using full addresses as usernames.
It also adds some shell tests to cover most of the functionality.
This patch adds a "chasquid-userdb" command line tool to check and add users
to chasquid's userdb files.
It's not pretty or very friendly, as it's meant to be used for testing for
now.
